"Sand, grit, et cetera. Anything that can come off the underside of a car, oils, grease, et cetera. Also just the volume of the water in and of itself," said Vermont stormwater program manager Padraic Monks.

To help reduce the amount of polluted runoff, and help stop erosion by slowing the flow, the state just announced an update to its municipal separate storm sewer system -- or MS4 -- general permit.

"It's going to bring those streams themselves back to meeting the Vermont water quality standards, which is important," said Monks.

The permit applies to 13 of the state's biggest cities and towns, as well as Burlington International Airport, UVM and the Agency of Transportation.

In other words they'll have three years to develop a detailed plan to clean up streams polluted by stormwater, and they'll have 20 years to carry that plan out.

"The first thing that jumped out at me was the really long time frame of 20 years," said Vermont Natural Resource Council Staff Scientist Kim Greenwood.

She said the permits should require waterways to be cleaned up sooner.

"There are a lot of analogies to human health. If you start looking at your diet and your exercise when you've put on 5 pounds that's a lot different than considering those things when you've put on 105 pounds. It just makes it that much easier the sooner you get to tackle a problem, and cheaper," said Greenwood.

Monks says the state wants to see the streams meet federally approved limits for water runoff, but at a pace that municipalities can handle.

"Providing a schedule of compliance that both meets the requirements of the law and the goals that the legislature has spelled out and also one that's feasible, you know, that can be implemented successfully by the municipalities. That was the huge challenge," Monks said.

The state estimates it will cost $100 million to clean up the waterways. The DEC says it will work with the legislature to try and find funding sources to help the municipalities.